-LRB- CNN -RRB- -- The parents of a 15-year-old girl who was gang-raped on a California high school campus urged the community Saturday to channel its anger over the event `` through positive action , '' according to a pastor .

At a Saturday community event at the campus where the attack took place , the Rev. Jim Wheeler , who said he was the family 's pastor at First Presbyterian Church in Richmond , read a statement from the teenager 's parents .

`` Stop the violence , '' Wheeler read . `` Please do not respond to this tragic event by promoting hatred or by causing more pain . We 've had enough violence already in this place . ''

Police say as many as 10 people were involved in the rape on October 24 in a dimly lit back alley outside Richmond High School , where a homecoming dance was taking place .

Another 10 people watched the attack without calling 911 , police say .

Five people have been arrested in connection with the attack .

A sixth person who was arrested is expected to be freed because of insufficient evidence , CNN affiliate KGO reported .

Authorities say the attack lasted for more than two hours . The victim , who was taken to a hospital in critical condition , was released Wednesday .

The parents ' statement urged the community to work to ensure that such an attack never happens again .

`` If you need to express your outrage , please channel your anger through positive action , '' they said , according to Wheeler .

`` Volunteer at a school . Go help a neighbor . Be courageous in speaking the truth and in holding people accountable . Work toward changing the atmosphere in our schools and in this community so that this kind of thing never happens again .

`` Please do not let this happen again . ''

@highlight

`` Please do not respond to this tragic event by promoting hatred , '' victim 's parents say

@highlight

Family 's statement read during community event at campus where attack took place

@highlight

Police say 10 people may have been involved in rape outside Richmond High School

@highlight

Five arrested in connection with attack , which occurred during homecoming dance